SQL CREATE INDEX

n relational database, Index will be the important mechanism for boosting performance.
Index is important like Index for a book that helps you quickly find the pages that you wanted to read, index on the column speeds data retrieval.

CREATE INDEX Statement will look like this:

CREATE [UNIQUE] INDEX [INDEX NAME]
ON TABLE [COLUMN NAME]

EXAMPLE :

Want to create a INDEX on Table Users which is including column names user_fname and user_lname.

SQL Statement:

CREATE INDEX user_name
ON Users (user_fname, user_lname)

 

转载于:https://www.cnblogs.com/zhoug2020/p/3328308.html